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Bubba disconnected all the vac lines from the heater box plenum actuators. I'll need to get new vac control hoses anyway, but I have no idea how these puppies hook up! There are 2 actuators, a larger vertical one at the driver's side end of the heater box and a smaller horizontally mounted one on top of the heater box near the passenger side of the transmission tunnel. The larger actuator has 4 vacuum fittings, a curved and a straight on either side. The smaller actuator has just 2 fittings, a straight and a curved.
Those of you who are looking at the heater box assembly below the passenger dash will know exactly what I'm describing. There are 4 vac lines coming off the driver's side heater control wheel which DO have color coding, and 2 coming off the passenger side heater control wheel which do not appear to be color coded.
Any pictures or schematics out there?
Last edited by Grinchia; 10-30-2009 at 10:19 PM.
Reason: needed more precise title
Giving myself a bump here...I looked at doc rebuild but couldn't find anything that looked like my '68 non-ac setup schematic. There are a total of 6 apparent bibs for a vacuum hose on 2 different actuators that live on my heater box. There are only 6 hoses coming off of my heater control vacuum manifold/switches, and one of them is a shorty that connects to a "T" off of the driver side vacuum switch. On of these hoses originally traversed the firewall, but I have no idea where it went after that as it was cut off flush with the firewall when I bought the car. Can anyone help me out here? A picture of the heater box in a '68 without air would be a good start...a schematic would be even better.
On a related note, the "octopus" vacuum hose harness that connects to the heater control unit in this car is showing it's age...does anyone know of a supplier of replacement vacuum CONTROL hoses? When I search the vendors all I seem to find are the larger vacuum hoses that do the work, not the little bitty control hoses that attach directly to the heater console thumbwheel switches...and terminate at the actuators on the heater box.
There are 4 vac lines coming off the driver's side heater control wheel which DO have color coding, and 2 coming off the passenger side heater control wheel which do not appear to be color coded.
The Chevrolet Chassis Service Manual for your year car has the diagrams you need. You should have a copy (along with a copy of the A.I.M.) if you do any work on your car.
The Chevrolet Chassis Service Manual for your year car has the diagrams you need. You should have a copy (along with a copy of the A.I.M.) if you do any work on your car.
Interesting...I have the AIM, but I have not to this point heard of the Chassis Service Manual...I'll do a search and see if I can locate one. The AIM does not seem to have the particular information I need. Lots of info on AC cars, not so much for mine.
That looks like it all right. I just looked carefully and what I took to be a second vacuum port on each of those actuators was really just a post for the vacuum hose flange to fasten to. I believe that should do it! Thank you.
Bubba disconnected all the vac lines from the heater box plenum actuators. I'll need to get new vac control hoses anyway, but I have no idea how these puppies hook up! There are 2 actuators, a larger vertical one at the driver's side end of the heater box and a smaller horizontally mounted one on top of the heater box near the passenger side of the transmission tunnel. The larger actuator has 4 vacuum fittings, a curved and a straight on either side. The smaller actuator has just 2 fittings, a straight and a curved.
Those of you who are looking at the heater box assembly below the passenger dash will know exactly what I'm describing. There are 4 vac lines coming off the driver's side heater control wheel which DO have color coding, and 2 coming off the passenger side heater control wheel which do not appear to be color coded.
Any pictures or schematics out there?
These diagrams will help for 1969-1970 heater vacuum systems. The old hoses have to be drilled out of some of the couplers and the new ones glued into place. Use a 1/8” bit. There are YouTube videos available.
Let me look at my 68 AIM....I don't remember many vacuum lines going to heater control on my 1968 non-a/c.... back in a sec.
Originally Posted by Grinchia
Giving myself a bump here...I looked at doc rebuild but couldn't find anything that looked like my '68 non-ac setup schematic. There are a total of 6 apparent bibs for a vacuum hose on 2 different actuators that live on my heater box. There are only 6 hoses coming off of my heater control vacuum manifold/switches, and one of them is a shorty that connects to a "T" off of the driver side vacuum switch. On of these hoses originally traversed the firewall, but I have no idea where it went after that as it was cut off flush with the firewall when I bought the car. Can anyone help me out here? A picture of the heater box in a '68 without air would be a good start...a schematic would be even better.
On a related note, the "octopus" vacuum hose harness that connects to the heater control unit in this car is showing it's age...does anyone know of a supplier of replacement vacuum CONTROL hoses? When I search the vendors all I seem to find are the larger vacuum hoses that do the work, not the little bitty control hoses that attach directly to the heater console thumbwheel switches...and terminate at the actuators on the heater box.
10-21-2009, 11:07 AM
1968 Non-AC Heater control vacuum hose schematic
